hissing noise in A/C

[motu1983]

Ok, i've noticed this for a while and my ex mentioned it the last time she was in my 06 sierra, but my AC makes a hissing noise when its on and its warm to hot outside. the sound closely resembles the sound that steam makes, but slightly muffled and it comes from somewhere behind the dash. I'm baffled by it but since its my work truck and i work 6 days a week, getting it in the shop is pretty hard to do. Has anyone else had a similar problem?

[ZZ327]

If you have a lower trim pickup, it wont have the plastic cover underneath the dash to block noise. The noise is Freon running through the Orifice and heat exchanger, Its normal.

 

Unless your a/c is actually starting to not work, you might have a small leak.

[pm26]

normal

[SoCalChris]

I'm pretty sure it's normal. I've never heard the hissing inside of my truck, but I've heard it many times when I get out and the A/C has been on. Most of the other cars that I've had do that also.

[Schmids5.3l]

Mine does it bad when I turn the truck off. It sounds like an occasional crunching/cracking/hissing noise. Then when I turn the truck off i get a big "pprrrrssshhhhh"

[motu1983]

thanks guys. i do have the WT trim level. So what part exactlydo i need to block off the noise?

[pm26]

thanks guys. i do have the WT trim level. So what part exactlydo i need to block off the noise?

 

<{POST_SNAPBACK}>

 

 

 

A new pair of good quality earplugs.

[ZZ327]

air box cover looks like this under the glove box.

you can see it if you click the interior shot

 

 

http://cgi.ebay.com/ebaymotors/Chevrolet-S...sspagenameZWDVW

 

 

I cant remember the specific name for it!

[frdfandc]

The easiest way to fix it is to turn the volume up.